A Solid Soaking…

The average date of the first frost in Boston is November 7th…it happened this morning…Boston slipped to 32 degrees at 6:04 AM. Some towns were in the teens at sunrise…Norwood 18 and Taunton 19! Tonight won’t be as bad as last night, we have pretty good cooling conditions right now and we will dip into 30s before temps level out as clouds arrive overnight.

Clouds will thicken up early tomorrow morning and rain will press in by late morning getting heavier in the afternoon when some downpours arrive. The overrunning rain will taper off tomorrow evening but the amplifying trough to our west will spin up another low in our offshore waters throwing more rain back into the area later tomorrow night through midday Friday. When it is said and done we are looking at 1-2 inches with higher amounts possible over SE Mass closer to possible convective elements.

The upper level cut-off remains to our west until it passes overhead on Sunday it will spin up additional lows offshore that appear to be a little too far out…but should be closely monitored. With the location of the upper level low to our west the more serious cold air will be delayed…arriving on Sunday. A mid level ridge will try to establish itself next week providing a warm up which is much more pronounced on the EURO. The GFS actually intensifies another low in the Maritimes keeping us under cyclonic flow early next week…coolish and somewhat cloudy. This is the first run with this scenario and we prefer the EURO in the extended regardless so we will side on the warmer solution.

The Euro has been much more consistent and much more correct than the GFS for the past 6 weeks. Though it did have a little trouble resolving this upcoming scenario several days ago. One radical run tipped me off to this issue when it curved a surface low westward from the Atlantic right over New England on Nov 7, when in reality we will end up with high pressure moving in and fair weather that day. Overall, the Euro continues to be the superior performer this Fall.

Topkatt, I feel like you have been a GFS critic for quite awhile this year. Maybe the GFS just isn’t “working” for NE these days. I vaguely remember you saying you liked the NAM recently. Should I just be looking at the NAM for now anyway?

Hi Longshot…
I’ve been critical of the GFS because it has not performed well. Through the years it has been one of my favorite medium range models to follow, but it started to miss alot in the last several months and I noticed that the Euro was doing a much better and more consistent job of picking out trends. But I keep watching the GFS to see if it comes back around. Perhaps a modification was made that I’m unaware of, and that isn’t doing the trick. I’ll have to dig a bit.

For short range, the NAM generally does quite well, but you still have to know when it’s being contaminated by bad info or suffering a case of convective feedback, for example. Experience in using it makes this easier to do.